Method for processing and precooling eggs



Nov. 12, 1940. A M V NY 2,221,343

' METHOD FOR PROCESSING AND PRECOOLING EGGS Filed March 2, 193B LNRB' LI q Q IINVENTOR Q 1 i i I 2% am inc-j I l 6% 6% 1 ATTORNEX inattemptingto area. If eggs are held Patented Nov. 12, 1940 UNITED STATES METHODroa rnocsssm o AND PREOOOL- IN G EGG Harry A. Mulvany, Berkeley, Calif.

Application March 2.

4 Claims;

This invention relates to a method and apparatus for processing andprecooling eggs.

For a-number of years it has been the prac tice to dip eggs for storageand distant shipment in an odorless and tasteless mineral .oil toprevent evaporation within the eggs. The equipment that has been usedfor this work in the past is wasteful in the matter of the oil that isused and acts detrimentally upon the quality of the eggs.

First, consider the oil to be used.. This oil is an odorless andtasteless mineral oil, and the present cost varies from forty cents pergallon to the large packer to about sixty cents per gallon to the smallpacker who only uses a suificient amount of oil to pack about-10,000cases of eggs in a season. I have made a careful study find out justwhat the oil does and the quantity necessary for satisfactory packing,and have found that each egg passed through a bath of heated to about160 Fahrenheit, will take out of the bath between .4 and .5 of a gram ofoil. I have further found that when the eggs are placed in their fillersand packed and permitted to stand for approximately 24 hours, to of theoil has disappeared, being absorbed by the packing material, or, inother words, the fillers and separators in the egg case. Plainlyspeaking, about 30% of the oil employed during the processing operationis absorbed by the shell and may betercmed useful oil, while about 70%of the oil used is lost in filler absorption.

The only purpose in heating the oil is to reduce its viscosity so theeggs will drain reason ably well. I have discovered that the viscositymay be reduced by the addition to the oil of a volatile solvent, such ascarbon tetrachloride, petroleum ether, and the like, and that by sodoing, heating of the oil is eliminated. It is well known in the artthat heating of the oil damages 'the eggs. For instance, when eggs areheld at room temperature, or about 68 Fahrenheit, for five days, it hasbeen found that the chalaziferous layer, or that layer which ties theyolk within the egg, weakens to such a point that a dark yolk conditionappearsfwhen the egg is candled, placing the egg in a low governmentgrade. The middle fiuid, or the socalled "firm white, also becomesweakened at the above temperature in five days to such a degree thatwhen the egg is broken to be fried the albumen covers a wider at lowtemperatures, these changes do not take place.

With'the common practice for processing eggs the best oil, where the oilis 1938, Serial No. 193,483 (01. 99-170) in oil which is heated to 160Fahrenheit, the eggs in passing through the oil, whether by submergence,spraying or otherwise, reach a temperature of approximately Fahrenheit,a temperature just below the coagulating point of 5 the albumen. Thishigh temperature is retained after the eggs leave the processingmachines and is only gradually reduced during a period of several hours,even though placed in iced refrigerator cars or cold storage, as it hasbeen 10 found that after 24 hours the eggs are still above the minimumtemperature required for best keep ing. This heating of the eggs to acomparatively high temperature during processing and a long period ofcooling following the same brings 11 about more rapid proteolysis.

By reducing the viscosity of the oil with the volatile solvent, heatingof the oil is entirely obviated, and in fact permits cooling of the oilto 30 Fahrenheit or less, thereby making it .pos- 20 sible to not onlyprocess the eggs but also to pre-cool the eggs prior to placing them inrefrigerator cars or storage. By a process of airblast and partialvacuum it is possible to remove the volatile solvent and the excess oil,leaving 25 the heavy oil in the shell of the egg. The eggs thus arriveat the market in a substantially fresh condition, as the quality of theegg has been little, if any, changed, and it may furthermore be statedthat the eggs have a better ap- 30 pearance, as all excess oil has beenremoved.

An apparatus employed for processing and precooling of eggs by my methodis shown by way of illustration in the accompanying drawing, in which-Fig. 1 is a central vertical longitudinal section of the apparatus;

Fig. 2 is a cross-section taken on line IIII of Fig. '1, said viewshowing the tank partially broken away;

Fig. 3 is a plan view of one of the egg carriers or frames; and

Fig. 4. is a side elevation of the egg carrier shown in Fig. 3.

Referring to the drawing in detail, and particu- 45 larly Fig. 1, Aindicates an elongated frame, at opposite ends of which are journaledstub-shafts 2 and 3. Secured to the shafts 3 are a pair of sprocketgears 4, and similarly secured on the shafts 2 are a pair of sprocketgears 5. Car- 50 ried by the sprockets 4 and 5 are a pair of sprocketchains which form an endless conveyor, and adapted to transmitcontinuous movement to said conveyor is a sprocket gear 6 which isdriven by a chain 1 from a motor-driven reduction 55 'by a fork andsimilarly removed. Arranged below the upper reach of the endlessconveyor,

- substantially midway of the frame A, is a tank 9, which is filled withan odorless and tasteless mineral oil, in which the eggs areimmersed tocoat the eggs with oil andto precool them. The oil is maintained at anapproximate temperature of 30 Fahrenheit by cooling coils it) throughwhich a brine solution or similar cooling medium is circulated. Theviscosity of the oil under the cool temperature maintained would beentirely too high, but is in this instance reduced to the desired degreeby the addition of a volatile solvent such as carbon tetrachloride, theamount of solvent required being approximately 20% by volume of the oilemployed.

Directly after immersion and precooling, the eggs are passed under ahood H, which is provided with a series of nozzles I2. Air underpressure from a blower I3 is delivered to the nozzles and the eggs arethus subjected to the action of an air blast on their upper surfaces andsimultaneously to a partial vacuum on their lower surfaces, as aninverted cone-shaped pan M is disposed below the path of travel of theegg frames and is connected with the suction side of the blower. Thisexposure of the eggs to a simultaneous air blastand partial vacuumcauses rapid removal of substantially all excess oil and at the sametime almost instantaneous evaporation of the volatile solvent, therebyfurther cooling'the eggs. A cyclone separator 95 is interposed betweenthe suctionpan I4 and the blower. All surplus oil removed from the eggsis there separated from the air and drains downwardly to a pump 16 whichreturns the.

oil to the tank 9.

After removalof the surplus oil and the volatile solvent, the egg framespass on to the point C, where one or more operators places fillers overthe eggs, inserts a fork and lifts the eggs together with the fillersfrom the frames and places the same in the egg crates, which, whenfilled, are closed by a cover and are ready for storage or for directplacement in refrigerator cars or the like. It will be understood thatone or more operators are also stationed at the opposite end of themachine, or the point indicated at B, and that they remove the eggs andfillers from the egg crates by means of a fork and place the same on theegg frames, and then remove the fillers and replace the same in emptycrates, which are transferred to the other end of the machine, where thefillers are again removed to permit repacking of the crates after theeggs have been processed and precooled.

While egg carriers or frames of different makes may be employed, Iprefer the type shown in 'Figs. 3 and 4. These frames consist of a pair.of side bars 28 connected by a plurality of spaced cross-arms 2i. Thesearms have "wave formed sides which form narrow and enlarged roundedspaces 22 between them to receive and support the individual eggs. Thearms are here shown as formed of wires which are welded or otherwisesecured with relation to each other in pairs, as indicated at 23. Theends are 'bent at right angles and form pairs of legs 26, which aresecured to the side bars, the height of the legs and the space 25between each pair of legs being such that the prongs of a fork may bereadily project laterally and outwardly from the central point of eachside bar. These pins support the egg frames with relation to the lugs onthe chains or endless conveyor and thereby permit the frames to travelin a horizontal plane when being loaded with eggs and while beingunloaded and also during the period when they are submerged in the oilin the tank. To bring about submergence, pairs of sprocket gears arerequired, as indicated at 21 and 28, and between them a. pair ofsprocket gears 29 under which the chains pass. To prevent tilting of theframes about their pivots while passing downwardly into the tank andthen upwardly again, laterally and outwardly projecting pins 30 areprovided at opposite ends of the side bars. These pins enter betweenguide bars 3|, as each frame passes down into the tank and then upwardlyagain. During this entire period the pins 30 are held between the guidebars and as such maintain the frames in a horizontal position. Othermeans may obviously be employed.

From the foregoing description, it should be apparent that eggs treatedby the process here described will retain their high grade quality andwill in no way be detrimentally affected, as they are not subjected toheat at any tinie during the processing period. Conversely, they arerapidly cooled during their immersion in the oil and during evaporationof the volatile solvent. Again, it should be noted that by the additionof thevolatile solvent it is possible to reduce the viscosity of the oilto any degree desired, thereby insuring a material saving of oil, saidsaving being further promoted by removal of excess oil when the eggs aresubjected to a simultaneous air blast and vacuum. In actual practice, asaving of substantially 50% over methods heretofore used has beenobtained.

While these and other features of the present invention have been moreor less specifically described and illustrated, I nevertheless wish itunderstood that various changes may be resorted to within the scope ofthe appended claims, and

that the materials and finish of the several parts employed may be suchas the judgment and experience of the manufacturer may dictate or otherconditions may demand.

During the operation of the process, considerable amounts of gases fromthe volatile solvent are liberated. To prevent these from afiecting theoperators, a hood E is provided to collect and carry them away.

Having thus described and illustrated my in vention, what I claim anddesire to obtain by Letters Patent is as follows:

1. The method of oil coating and precooling eggs for cold storage orshipment in refrigerator cars which consists in adding to the oil asufflcient quantity of a solvent to reduce the oil to a water-likeconsistency when maintained at a refrigerating temperature, subjectingthe eggs to the cooling action of the oil at such temperature andmaintaining them in the oil until the eggs have been cooled to arequired temperature, and

ator cars which consists in adding to the oil asufilcient quantity ofcarbon tetrachloride to reduce the oil to a water-like consistency whenmaintained at a refrigerating temperature, subjecting the eggs to thecooling and coating action.

\ of the oil at such temperature and maintaining them in the oil untilthe eggs have been cooled throughout to a required temperature, and thenremoving and draining the eggs and evaporating the carbon tetrachloride.

3. The method of coating and precooling eggs with oil for cold storageor shipment in refrigerator cars which consists in subjecting the eggsto the cooling and coatingaction of an oil containing carbontetrachloride in suflicient amount to render the same of water-likeconsistency when maintained at a refrigeratingtemperature, maintainingthe eggs in the oil at such temperature until they have been cooled to arequired temperature throughout, removing the eggs and draining theexcess oil therefrom.

4. The method of coating and precooling eggs with oil for cold storageor shipment in refrigerator cars which consists in subjecting theeggs tothe cooling and coating action of an oil containing a solvent insuflicient amount to render the same of water-like consistency whenmaintained at a refrigerating temperature, maintaining the eggs in theoil at such temperature until they 10 have been cooled to a requiredtemperature throughout, and then removing the eggs and evaporating thesolvent.

HARRY A. MULVANY.

